Refer to the exhibit. Which statement describes the effect that the Router1 configuration has on devices in the 172.16.16.0 subnet when they try to connect to SVR-A using Telnet or SSH?
A. Devices will not be able to use Telnet or SSH.
B. Devices will be able to use SSH, but not Telnet.
C. Devices will be able to use Telnet, but not SSH.
D. Devices will be able to use Telnet and SSH.
Answer: B
Explanation/Reference:
当在R1上配置如下图,其上 72.16.16.0网段试图telnet或者ssh SVR-A的时候,哪一个描述是正确的?
题目考查的是ACL用法,首先我们看图示
F0/0 是in方向,eq应该放在目的主机的后面,源主机是随机端口发出访问
f0/1也设置为in方向,只能控制返回的数据,这里eq应该放在源主机也就是SVR-A的后面
所以list 100中10生效,20 无效。list 101中 10生效,20无效。
最后默认都拒绝,所以只允许ssh
——————————————————————————————————————————
——————————————————————————————————————————
我在Packet Tracer上显示的结果是数据包到达F0/1后(却不是F0/0)被丢弃,想不明白,求指导啊。。。。,